وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا
قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «مَنْ حَلَفَ بِغَيْرِ اللَّهِ فَقَدْ أَشْرَكَ»
Ibn Umar told that he heard God’s Messenger say, “He who swears by anyone but God is a polytheist.”
Mishkat al-Masabih 3286, Book 16, Oaths and Vows, Hadith 14. 1 min read