Abu Dawud

Benefits and Issues:
Indeed, goodness and blessing in every individual and every thing can only occur when Allah, the Mighty and Majestic, has decreed it therein. Therefore, it is obligatory that one always asks Allah, the Mighty and Majestic, alone for it. Likewise, any evil found in a person or thing is also by the will of Allah, the Mighty and Majestic, so seeking protection from it should also be sought only from Allah, the Exalted. Especially, the matter of the wife is very important; comparatively, the wife may also supplicate to Allah, the Exalted, for goodness regarding her husband and seek refuge from his evil.
Even though there is no explicit text or clear statement (regarding this), and it is not necessary for her to hold the forelock (of her husband) for this purpose.

Commentary: See, the benefits of Hadith: 1918.

Benefits and Issues:
➊
A wife, slave-girl, cow, buffalo, horse, etc., are all blessings from Allah, but some of them may have such habits that become a source of constant trouble. Therefore, one should pray to Allah that only good is obtained from them and that no harm comes.

➋
A wife or slave-girl can be disrespectful, can be ill-mannered, or due to lack of intelligence, may do something that causes financial loss to the husband or owner, or affects his honor. Only Allah can protect from their evil. Similarly, a horse can be stubborn, a cow or buffalo can be one that kicks or gives little milk. To be saved from these difficulties, help and success are sought from Allah. On the contrary, if they possess good qualities, it is a favor from Allah, due to which the owner or husband attains comfort and happiness, and such a woman or animal can prove to be helpful in goodness. For this goodness, supplication is made to Allah.

➌
The head is the most important part of the body of a human or animal. Placing the hand on the head while supplicating has the purpose that Allah makes this human or animal beneficial for us. And Allah knows best.