Guru Ram Das had three sons, Prithia, Mahadev, and Arjan. He had to decide who would be Guru next. Guru Ram Das's cousin visited him and said, "My son is getting married, will you come and bless the wedding?" The Guru couldn't go so he decided to send one of his sons. He asked Prithia his oldest son. Prithia complained and didn't want to go. Guru Ram Das went to Mahadev and asked him, "Mahadev, will you go to Lahore and represent me at a wedding?" Mahadev only wanted to meditate and had nothing to do with the world. "It's all Maya, I won't know what to say or do, please don't send me." So his father the Guru had compassion and let him stay. Next Guru ji went to his youngest son, Arjan and asked him to go in his place. "Yes father, as you wish. I'm lucky to even have you ask. I'll do what you say." said Arjan. Then the Guru told him, "Go to Lahore, bless the wedding. When the wedding is over, share the light of the teachings of Guru Nanak with the people there and take care of the poor. Listen to me son, do not come back until you receive a letter from me." Arjan said, "I'll do just as you say my beloved Guru father. I shall leave right away."
So Arjan left for Lahore. The wedding was full of good food and people. The people were pleased with how Arjan acted and the things he said. Arjan missed his father the whole time. So someone told him, "Write a letter to your father and ask him to send you back." So Arjan wrote a short a beautiful letter of poetry telling of his longing to see the Guru: "My mind is thirsty for the sight of you. I am always, always a sacrifice to you beloved saint..." And he sent a Sikh to deliver the letter to the Guru. When Prithia saw the Sikh coming he recognized him and met him at the door. "Have you brought anything from my brother?" he asked. "Yes, I have a letter from Arjan for the Guru." Prithia said, "I'll give it to the Guru, give it to me. My father wants him to stay there longer" When Prithia read the letter he became jealous of how beautiful the poetry was and he hid the letter. The Sikh came back to Arjan and told him, "Prithia says your father wants you to stay longer and he will give the letter you wrote to the Guru." Arjan knew that Prithia was a liar and so he wrote a second letter: "Your face is beautiful and your words are pleasant. I haven't seen you in such a time, without seeing you I have no peace. I am a sacrifice to you my divine friend..." Arjan told his messenger to deliver it only to the Guru.
When the Sikh arrived Prithia met him there. "Give me the letter!" The Sikh tried to protest but Prithia said, "I am the Guru's oldest son, do as I say. The Guru wants him to stay there we will bring him back soon. Go." When Prithia read this second letter he got even more jealous of how beautiful this poetry was. The messenger returned and told Arjan of how Prithia forced him to give up the letter. Arjan couldn't return as there was no letter from his father yet. He was getting sick from missing the Guru. He couldn't sleep and forgot to eat. He felt empty without seeing his father. He wrote another letter of poetry which was full of devotion: "A second without you is like endless darkness. When can I see you, I can't sleep without seeing your court. I am a sacrifice to you...." At the end of the note he wrote: "#3" so his father would know he wrote two others. "Don't be tricked and only give this personally to my father himself." When the messenger arrived to the Guru's court Prithia was waiting but the messenger hid and waited for Prithia to leave. Then he snuck in and put the letter at the Guru's feet. "Oh, a letter from Arjan, I was wondering when he would request to come back. It's a very beautiful letter but why does it say '#3' on it?"
The messenger told Guru Ram Das how Prithia took the other letters. Guru ji called for Prithia and asked him, "Did you take the other two letters?" "No, I didn't.... I don't know, I forgot." The Guru had someone go in to Prithia room and find the letters, which they did. The Guru sent the messenger back to tell Arjan to return. The Guru announced to everyone, "I tested Prithia and found him to be a liar and a cheat." When Arjan returned he was very happy to see his father finally. The Guru told him, "You have written 3 letters, write a fourth and complete the poem." Then Arjan wrote the final letter: "How fortunate I am to see you dear saint. I have found God in my heart. I want to serve as a slave. I am a sacrifice, a sacrifice..."
The poem was so beautiful the Guru hugged him and said, "This poem is so full of longing it has the power of a thousand shabds. It is called Shabd Hazare. The Guruship goes to the most humble, serviceful and devoted. I give it to you. You are now Guru Arjan." Guru Arjan Dev ji now humbly carried the throne of Guru Nanak. He never stopped writting love letters to God and the Guru Granth Sahib is filled with his beautiful poetry.