Shaking hands with a non-mahram man

This is one of the cases where incorrect social customs have taken precedence over the laws of Allah, to such an extent that if you try to talk to people and show them evidence that this is wrong, they will accuse you of being backward, having a complex, trying to break family ties, doubting their good intentions, etc.

Shaking hands with female cousins, brothers’ wives and uncles’ wives is now easier than drinking water in our society, but if we look properly we will understand the seriousness of the matter.

The Prophet (peace and blessings of Allah be upon him) said:

“If one of you were to be stabbed in the head with an iron needle it would be better for him than touching a woman whom he is not permitted to touch.”
(Reported by al-Tabaraani, 20/212; see also Sahih al-Jaami’, 4921).

There is no doubt that this is an act of Zinaa, because the Prophet (peace and blessings of Allah be upon him) said:
"The eyes may commit Zinaa, the hands may commit Zinaa, the feet may commit Zinaa and the private parts may commit Zinaa.
" (Reported by Imam Ahmad, 1/412; see also Sahih al-Jaami', 4921).

Is there anyone more pure in heart than Muhammad (peace and blessings of Allah be upon him)? Yet still he said,
“I do not shake hands with women.”
(Reported by Imam Ahmad, 6/357; see also Sahih al-Jaami’, 7054, and al-Isaabah, 4/354, Daar al-Kitaab al-’Arabi edition).

And he said, "I do not touch the hands of women."
(Reported by al-Tabaraani in al-Kabeer, 24/342; see also Saheeh al-Jaami', 7054 and al-Isaabah, 4/354, Dar al-Kutub al-'Arabi edition).

‘Aa’ishah (may Allah be pleased with her) said:
“No, by Allah, the hand of the Messenger of Allah (peace and blessings of Allah be upon him) never touched the hand of a (non-mahram) woman. He received bay’ah (pledge of allegiance) from them by word only.”
(Reported by Muslim, 3/489).

Let them fear Allah, those people who threaten their pious wives with divorce if they do not shake hands with their brothers.

We should also note that placing a barrier such as a piece of cloth is of no use; it is still haram to shake hands with a non-mahram woman.