`Abd al-Rahman bin `Abd Allah al-Ba`li writes at the beginning of his commentary on Ikhsar al-mukhtasarat at the beginning of the book of purification

Imam Ahmad, may Allah Most High be merciful with him, did not author a book in fiqh. Rather, his companions took his madhhab from his statements, actions, answers, and others [sources]. His statements “one should not,” “it is not fit,” “I find it ugly,” “it is ugly,” and “I do not opine that” [respectively: la yanbaghi, la yasluh, astaqbihahu, huwa qabih, la arahu] indicate prohibition. However, some scholars interpreted “one should not” [la yanbaghi] in some of his statements to indicate offensiveness.

There are two opinions regarding [Imam Ahmad] saying “I find it offensive,” “it does not please me,” “I do not like it,” “I do not find it to be good,” “whoever asked should do such-and-such to be say” [respectively: ukrihahu, la yu`jibuni, la uhibbuhu, la astashinuhu, ya`al al-sa’ilu ihtiyatan]

[Imam Ahmad saying] “I like such-and-such,” “it pleases me,” or “it is more pleasing to me” [uhibbu kadha, yu`jibuni, `ajabb ilayya] indicate that something is preferable.

[ From Kash al-mukhaddarat 1:41. cf. Kashshaf al-qina` 1:14]