هُمَا يَتَفَايَدَانِ بِالمَالِ بَيْنَهُمَا

They two give, of the property, each to the other; or profit, or benefit, each other therewith: (ISh, T, O, K:) you should not say يَتَفَاوَدَانِ: (K:) and هما يتفايدان العِلْمَ They two impart knowledge, each to the other: (K in article فود [q. v.]:) or, in the opinion of MF, both of these verbs are allowable. (TA.)