Muwatta Malik · Hadith 340

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَقْصُرُ الصَّلاَةَ فِي مَسِيرِهِ الْيَوْمَ التَّامَّ ‏.‏

Yahya related to me from Malik from Ibn Shihab from Salim ibn Abdullah that Abdullah ibn Umar used to shorten the prayer when he travelled for a whole day

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).