What is the ruling on saying: "I will do this for your sake"? May Allah reward you with goodness.

There is no harm in saying: "As long as you pray, do whatever you wish," and the proof for this is the hadith from Anas ibn Malik, may Allah be pleased with him, that the Prophet, peace and blessings be upon him, prayed at night during Ramadan, and some people stood behind him. He lightened the prayer, then entered his house and prayed, then came out and lightened the prayer again. When morning came, they mentioned that to him, and he said: "I only did that for your sake."