Musannaf Ibn Abi Shayba 9:949

Shababa narrated to us, from Warqa’, from Ibn Abi Najih, from Mujahid, regarding [the verse]: "Or in what you conceal in your hearts" [referring to] the proposal to women. He said: It is the man saying to the woman, "You are beautiful," "You are beneficial," and "You are dear to me." Let the mention of his proposal be within himself; he should not disclose it to her. All of this is permissible and well-known.