From his father (Ibn 'Umar) that the Prophet ﷺ heard 'Umar saying: "By my father, By my father!" So he said: "Verily Allah prohibits you from swearing by your father." So 'Umar said: "By Allah I did not swear by him after that, neither intentionally nor in narrating."  

سَمِعَ النَّبِيُّ ﷺ عُمَرَ وَهُوَ يَقُولُ وَأَبِي وَأَبِي فَقَالَ أَلاَ إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ فَقَالَ عُمَرُ فَوَاللَّهِ مَا حَلَفْتُ بِهِ بَعْدَ ذَلِكَ ذَاكِرًا وَلاَ آثِرًا قَالَ وَفِي الْبَابِ عَنْ ثَابِتِ بْنِ الضَّحَّاكِ وَابْنِ عَبَّاسٍ وَأَبِي هُرَيْرَةَ وَقُتَيْلَةَ وَعَبْدِ الرَّحْمَنِ بْنِ سَمُرَةَ  

That the Messenger of Allah ﷺ came across 'Umar while he was on his mount, and he was swearing by his father. So the Messenger of Allah ﷺ said: "Verily Allah prohibits you from swearing by your fathers. So let the one who swears, swear by Allah, or be silent."  

أَنَّ رَسُولَ اللَّهِ ﷺ أَدْرَكَ عُمَرَ وَهُوَ فِي رَكْبٍ وَهُوَ يَحْلِفُ بِأَبِيهِ فَقَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ لِيَحْلِفْ حَالِفٌ بِاللَّهِ أَوْ لِيَسْكُتْ  

That Ibn 'Umar heard a man saying: "No by the Ka'bah" so Ibn 'Umar said: "Nothing is sworn by other than Allah, for I heard the Messenger of Allah ﷺ say: 'Whoever swears by other than Allah, he has committed disbelief or shirk.'"  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ مَنْ حَلَفَ بِغَيْرِ اللَّهِ فَقَدْ كَفَرَ أَوْ أَشْرَكَ