Kind treatment to ones wife
خيرُكم خيرُكم لأهلِه ، وأنا خيرُكم لأهلي
The best of you is the one who is best to his wife, and I am the best of you to my wives [Saheeh Targheeb no. 1925]
‘Allamah al-Mubaarkfoori rahimahullah said: “That is: his children and his relatives. It was said his wives and relatives” [Tuhfatul-Ahwadhi (10/269)]
Imam al-Munaawi rahimahullah said: “His children and relatives. This is what Ibn Atheer said” [Fayd al-Qadir (3/495)]
However, there is another wording of the same Hadith which states:
خيرُكم خيرُكم للنِّساءِ
The best of you is the best of you to your women
[Saheeh Targheeb no. 1925]
as-San’aani rahimahullah said:
“That is: his wives. It is a specific admonishment for doing good towards the wives in general, except they are more deserving of good companionship. It is also carried to mean the daughters, sisters, and their like” [Tanweer Sharh Jami as-Sagheer (6/33)]
Shaikh Ibn ul-‘Uthaymeen rahimahullah said that the intent of women in one Hadith is the family as comes in the other Hadith [See: Sharh Riyaadhus-Saliheen (3/569)]
So the Hadith is in regards to the wives and other than them of the family.
And Allah knows best
Faisal Ibn Abdul Qaadir Ibn Hassan
Abu Sulaymaan