Muhajir bin Qunfud reported,

He came to the Prophet ﷺ while he was urinating and greeted him with the salaam, but the Prophet did not respond until he had performed ablution. Then he apologized to him, saying, "I disliked mentioning Allah except in a state of purity." Or he said, "in a state of cleanliness."

عن المهاجر بن قنفذ

أنه أتى النبي ﷺ وهو يبول فسلم عليه، فلم يرد عليه السلام حتى توضأ، ثم اعتذر إليه فقال: إني كرهت أن أذكر الله عز وجل إلا على طهر. أو قال: على طهارة.