Sunan Ibn Majah, Book 5, Hadith 1314 (In-Book) ⓘ
It was narrated from Abu Dharr that the Prophet said: “Offer prayer on time, and if you reached the Imam leading them in prayers (on time), then perform it with them, and you will be safe with your prayer, otherwise it will be voluntary for you.”
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي عِمْرَانَ الْجَوْنِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ الصَّامِتِ، عَنْ أَبِي ذَرٍّ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ " صَلِّ الصَّلاَةَ لِوَقْتِهَا فَإِنْ أَدْرَكْتَ الإِمَامَ يُصَلِّي بِهِمْ فَصَلِّ مَعَهُمْ وَقَدْ أَحْرَزْتَ صَلاَتَكَ وَإِلاَّ فَهِيَ نَافِلَةٌ لَكَ " .
also referenced under: Hadith 1256 (Reference) & Volume 2, Book 5, Hadith 1256 (DarusSalam)