فإن أريد الجمع بين شيئين في أمر من غير قصد إلى كون أحدهما ناقصا والآخر زائدا
If the intention is simply to unite two things in one respect, without making one deficient and the other superior.
Sometimes the speaker wishes to state equality in a shared feature, not to assign one side the role of standard and the other the role of dependent example. Forcing an ordinary subject/comparison-term hierarchy can suggest a preference that is absent from the intention.
A direct judgment of mutual resemblance can then be clearer: “The two friends resemble one another in patience” may be better than “The first is patient like the second,” because it avoids implying that only one is the reference measure.