I heard Messenger of Allah (ﷺ) say: But between them are certain doubtful things which many people do not recognize. He who guards against doubtful things keeps his religion and his honor blameless, but he who falls into doubtful things falls into what is unlawful.
“The Messenger of Allah (ﷺ) said to Abu Bakr: ‘When do you pray Witr?’ He said: ‘At the beginning of the night, after ‘Isha’.’ He said: ‘And you, O ‘Umar?’ He said: ‘At the end of the night.’ The Prophet (ﷺ) said: ‘As for you, O Abu Bakr, you have seized the trustworthy handhold (i.e., you want to be on the safe side), and as for you, O ‘Umar, you have seized strength (i.e., you are confident that you have the resolve to get up and pray Witr).’” Another chain with similar meaning.