ما هي الأدلة من الكتاب والسنة على جواز صلاة نافلة واحدة بنية جمع نوافل متعددة؟

The mosque greeting (تحية المسجد) and the prayer following ablution (سنة الوضوء) are not intended as ends in themselves. Rather, what is required is to pray after performing ablution and upon entering the mosque before sitting down. Any obligatory or supererogatory prayer suffices for them, and scholars have agreed upon this. The mosque greeting is evidenced by the hadith: "When one of you enters the mosque, let him not sit until he prays two rak'ahs." The prayer following ablution is evidenced by the hadith of Bilal: "I have not done any deed in Islam more hopeful of benefit to me than that I do not purify myself with a complete purification at any hour of night or day except that I pray with that purification what Allah has decreed for me to pray."