Jinns present in the service of Holy Imams (A.S.)

Sadeer Sairfi narrates that Imam Muhammad Al-Baqir (as) ordered him to go out from Medina for some errand. He was still on his way when a man overtook him and gave him a letter that had a fresh seal on it. He opened the letter and found that it was from the Imam a.s.). The letter contained fresh instructions for him. He was wondering how the carrier could reach him so fast that he had already travelled more than fair distance towards his destination. Then he thought, the carrier must be an angel to have reached him with the Imam (as)’s missive so fast!.
On his return he asked the Imam (as), “O my Master! Did you send that letter to me with some angel?” He replied, “No! It was a Jinn who is generally present in our service!”
Abu Hamza Shimali narrates that he was once travelling with Imam Ja’far As-Sadiq (as) half way between Mecca and Medina when he noticed a dog coming in their direction. When it came near them, he saw that it was a bird. Surprised, he asked the Imam (as), “O my Master! What is this?” He replied, “This a Jinn who brings the news of the death of Hisham.”
Kulaini narrates from Saad Askaf that he went to the presence of Imam Muhammad Al-Baqir (as). When he was taking leave, the Imam (as) said, “Wait awhile!” In the meanwhile some tall persons with yellowish faces entered the place of the Imam (as). I asked the Imam (as), “Who these people are?” The Imam (as) said, “These are Jinns, your brothers In Faith. They have come here to seek clarification about things Halal and Haram.”
Imam Muhammad Al-Baqir (as) narrates that, one-day, Amir’ul-Mu’mineen ‘Ali (as) was seated on the pulpit of Masjid al-Koofa when a serpent entered the threshold of the mosque. The people tried to kill it. Amir’ul-Mu’mineen ‘Ali (as) prevented them from doing so. The serpent came near the pulpit, rose and greeted the Imam (as). Amir’ul-Mu’mineen ‘Ali (as) inquired the reason for its coming there. It said, “O Master! I am Omer bin Othman. My father was appointedc the head of the Jinn by you. He is no more. Before his demise he had asked me to come to your presence and take your orders.”
Amir’ul-Mu’mineen ‘Ali (as) said, “I advise you to be pious! I order you too to take the place of your father and continue discharging the duties of the chief of the Jinns.’
The narrator asked Imam Muhammad Al-Baqir (as) if Omer bin Othman ever comes to him and is he duty bound to obey him? The Imam (as) replied, “Yes!”