Hadith: Do not do so. If any of you prays in his house and finds that the Imām has not prayed, he should pray along with him; and that will be a supererogatory prayer for him

عن جابر بن يزيد بن الأسود، عن أبيه، أنه صلى مع رسول الله صلى الله عليه وسلم وهو غلام شاب، فلمَّا صلَّى إذا رجلان لم يُصَلِّيا في ناحية المسجد، فدعا بهما فجيء بهما تَرْعُد فَرائِصُهما، فقال: «ما منعكما أن تُصَلِّيا معنا؟» قالا: قد صلَّينا في رِحالنا، فقال: «لا تفعلوا، إذا صلَّى أحدكم في رَحْله ثم أدرك الإمام ولم يُصَلِّ، فليُصلِّ معه فإنها له نافلة».
[صحيح] - [رواه أبو داود والترمذي والنسائي وأحمد والدارمي]

Jābir ibn Yazīd ibn al-Aswad reported that his father prayed along with the Messenger of Allah (may Allah's peace and blessings be upon him) when he was a young boy. When he (the Prophet) had prayed, there were two people (sitting) in the corner of the mosque; they did not pray (along with the Prophet). He called for them. They were brought trembling (before him). He asked: "What prevented you from praying along with us?" They replied: "We have already prayed in our houses." He said: "Do not do so. If any of you prays in his house and finds that the Imām has not prayed, he should pray along with him; and that will be a supererogatory prayer for him."
Sahih/Authentic. - [At-Tirmidhi]

Explanation

Yazīd ibn al-Aswad reports that he prayed along with the Messenger of Allah (may Allah's peace and blessings be upon him) when he was a young boy. When the Prophet (may Allah's peace and blessings be upon him) had prayed, he saw two people who were sitting in the corner of the mosque and did not pray with him. The Prophet (may Allah's peace and blessings be upon him) ordered the Companions to bring those two men. They were brought to him trembling and disturbed out of fear. The Prophet (may Allah's peace and blessings be upon him) asked them: "Why did you not pray with us?" They replied: "We have already prayed in our houses." He said: Do not do this again. If any of you prays in his house and finds that the Imām is praying, he should pray along with him, and this would bring him greater reward. The first prayer would be considered the obligatory prayer, and the second will be a supererogatory prayer.