[Machine] The Prophet ﷺ used to delay the Dhuhr prayer when he wanted to combine it with the Asr prayer while traveling, until the beginning of the Asr prayer time.
كَانَ رَسُولُ اللهِ ﷺ إِذَا أَرَادَ أَنْ يَجْمَعَ بَيْنَ الظُّهْرِ وَالْعَصْرِ فِي السَّفَرِ أَخَّرَ الظُّهْرَ حَتَّى يَدْخُلَ أَوَّلُ وَقْتِ الْعَصْرِ
When the Messenger of Allah ﷺ intended to combine two prayers on a journey, he delayed the noon prayer till came the early time of the afternoon prayer, and then combined the two.
كَانَ النَّبِيُّ ﷺ إِذَا أَرَادَ أَنْ يَجْمَعَ بَيْنَ الصَّلاَتَيْنِ فِي السَّفَرِ أَخَّرَ الظُّهْرَ حَتَّى يَدْخُلَ أَوَّلُ وَقْتِ الْعَصْرِ ثُمَّ يَجْمَعُ بَيْنَهُمَا
Yahya related to me from Malik from Da'ud ibn al-Husayn from al- Araj from Abu Hurayra that the Messenger of Allah ﷺ joined dhuhr and asr on his journey to Tabuk.
أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَجْمَعُ بَيْنَ الظُّهْرِ وَالْعَصْرِ فِي سَفَرِهِ إِلَى تَبُوكَ
When the Messenger of Allah ﷺ intended to combine two prayers on a journey, he delayed the noon prayer till came the early time of the afternoon prayer, and then combined the two. (Using translation from Muslim 704b)
«كَانَ النَّبِيُّ ﷺ إِذَا أَرَادَ أَنْ يَجْمَعَ بَيْنَ الصَّلَاتَيْنِ فِي السَّفَرِ أَخَّرَ الظُّهْرَ حَتَّى يَدْخُلَ أَوَّلُ وَقْتِ الْعَصْرِ ثُمَّ يَجْمَعُ بَيْنَهُمَا»