Is one who does not pray the closing two units with the imam considered to have not prayed with the imam until he departs?
Machine translationRead the Arabic original
Question : The questioner says: Is one who does not pray the two closing units with the imam considered to have prayed with the imam until he departs?
Answer : No. He says: What about one who lags behind the imam in the last two units, which include the closing, and did not pray with the imam, but continued the prayer in the tahajjud? Is it said that he stood with the imam until he departed, or not? The answer is no, he did not stand with the imam until he departed. Consequently, the standing of the night is not recorded for him, because the Prophet (peace and blessings be upon him) said:Jami` at-Tirmidhi 806Sahih (Darussalam).
Answer : No. He says: What about one who lags behind the imam in the last two units, which include the closing, and did not pray with the imam, but continued the prayer in the tahajjud? Is it said that he stood with the imam until he departed, or not? The answer is no, he did not stand with the imam until he departed. Consequently, the standing of the night is not recorded for him, because the Prophet (peace and blessings be upon him) said:
Indeed, whoever stands (praying) with the Imam until he finished, then it is recorded for him that he prayed the whole night.
من قام مع الإمام حتى ينصرف كتب له قيام ليلة
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، لقاء[3من40]من لم يصلي مع الإمام الختمة يكون ممن لم يصلي مع الإمام حتى ينصرف؟!ابن عثيمين-كبارالعلماء — youtube.com
The Arabic text is a machine transcription of the audio recording.