It has reached us in the Book of Siyar, through Urwah (may Allah have mercy on him), from Sayyidah Aishah (may Allah be pleased with her), from the Prophet (peace and blessings be upon him), that he (peace and blessings be upon him) said: "I will never seek help from a polytheist." And the wording (of this hadith) is general.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / Q20407
Sayyiduna Zayd bin Thabit (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) instructed me to learn the writing of the Jews, and he said: "By Allah, I do not feel safe with the Jews in the matter of my writing." I learned the writing within half a month.
Abu Dawud (may Allah have mercy on him) said: I became proficient in it within half a month. My father said: I used to write for him (peace and blessings be upon him) when a letter was to be written, and I would read for him when a letter came.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20407
Azhar bin Rashid said: Anas bin Malik (may Allah be pleased with him) used to narrate hadiths to his students, and when he narrated something to them that they did not understand, they would go to Hasan (may Allah have mercy on him) to learn its explanation. One day Anas bin Malik (may Allah be pleased with him) narrated a hadith to them, that the Messenger of Allah (peace and blessings be upon him) said: "Do not seek light from the fire of the polytheists, and do not engrave Arabic on your rings." The students of Anas bin Malik (may Allah be pleased with him) came to Hasan (may Allah have mercy on him) and said: Today Anas narrated a hadith to us whose meaning we do not know. He asked: What did he narrate to you? They mentioned it. He said: Yes. As for his saying, 'Do not engrave Arabic on your rings,' it means: do not engrave 'Muhammad' on your rings. And as for his saying, 'Do not seek light from the fire of the polytheists,' it means: do not consult the polytheists in any of your affairs. The confirmation of this is in the Book of Allah: "O you who believe, do not take as intimates those other than yourselves; they will spare no effort to ruin you." [Surah Al Imran: 118]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20408
Iyad al-Ash'ari (may Allah have mercy on him) said: Abu Musa al-Ash'ari (may Allah be pleased with him) came with a delegation to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), and with him was a Christian scribe. Sayyiduna Umar (may Allah be pleased with him) was greatly impressed when he saw his memory. He said: Tell your scribe to read us a letter. Abu Musa (may Allah be pleased with him) said: He is a Christian; he does not enter the mosque. Sayyiduna Umar (may Allah be pleased with him) rebuked him and was about to punish him, and said: Do not honour them when Allah has humiliated them, do not bring them near when Allah has kept them distant, and do not trust them when Allah has declared them untrustworthy.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20409