مَنْ حَلَفَ بِغَيْرِ اللَّهِ، فَقَدْ أَشْرَكَ
Translation: Whoever swears by other than Allah is given a grave warning concerning associating others with Allah.
Source: الترمذي
حَلَفَ means “swore an oath,” and بِغَيْرِ اللَّهِ means “by other than Allah.” In فَقَدْ أَشْرَكَ, فَـ connects the consequence and قَدْ adds emphasis.
An oath involves a serious invocation and recognition of greatness. The report therefore strongly warns against swearing by anyone or anything other than Allah. Its wording must not be used by a beginner to pronounce a final judgment on a particular individual’s faith or fate.