I said to the Messenger of Allah ﷺ: Are there two prostrations in Surah al-Hajj? He replied: Yes; if anyone does not make two prostrations, he should not recite them.
قَالَ قُلْتُ لِرَسُولِ اللَّهِ ﷺ أَفِي سُورَةِ الْحَجِّ سَجْدَتَانِ قَالَ نَعَمْ وَمَنْ لَمْ يَسْجُدْهُمَا فَلاَ يَقْرَأْهُمَا