Praise be to Allaah.
Firstly:
It is not prescribed to place the hands over the face after
finishing prayer or after finishing du’aa’. The best of guidance is the
guidance of our Prophet Muhammad (peace and blessings of Allaah be upon
him). When he said the salaam (at the end of prayer) he would pray for
forgiveness three times, but he did not wipe his face with his hands after
saying the salaam or after saying du’aa’.
It was narrated that Thawbaan (may Allaah be pleased with
him) said: When the Messenger of Allaah (peace and blessings of Allaah
be upon him) had finished his prayer, he would pray for forgiveness three
times, and say: “Allaahumma anta al-salaam wa minka al-salaam, tabaarakta
yaa dhaa’l-jalaali wa’l-ikraam (O Allaah, You are al-Salaam (the One Who
is free from all defects and deficiencies) and from You is all peace,
blessed are You, Possessor of majesty and honour)”. Narrated by Muslim
(591).
In the answer to question no.
39174 we stated that it is not
prescribed to wipe the face with the hands after saying du’aa’.
Secondly:
Shaking hands is something that is mentioned and encouraged
in sharee’ah, and it is a cause of sins being forgiven.
It was narrated that al-Bara’ ibn ‘Aazib (may Allaah be
pleased with him) said: The Messenger of Allaah (peace and blessings of
Allaah be upon him) said: “There are no two Muslims who meet and shake
hands, but they will be forgiven before they part.” Narrated and classed as
hasan by al-Tirmidhi (2727); narrated by Ibn Maajah (3703); classed as
saheeh by al-Albaani in Saheeh al-Targheeb, 2718.
Some people put their hands over their hearts after greeting
and shaking hands with someone, but this is contrary to the meaning of
shaking hands both in linguistic terms and in Islamic terminology. There is
no evidence for that in the Sunnah, and there is no report – as far as we
know – which says that any of the salaf did that.
Shaking hands means clasping the palm of one hand against the
palm of the other person’s hand.
Al-Raaghhib al-Asfahaani said:
Shaking hands means stretching the palms of the hands
(against one another).
Ghareeb al-Qur’aan (1/282).
And Ibn Hajar al-‘Asqallaani said:
Shaking hands means clasping the palm of one hand against the
palm of the other hand.
Fath al-Baari (11/54)
Shaking hands is sufficient to greet a person in accordance
with the Sunnah. However, if the people are accustomed to placing the hand
over the heart after shaking hands or greeting someone as a way of showing
honour to them, then we hope that there is nothing wrong with it, but we
should not attribute that to the Sunnah of the Prophet (peace and
blessings of Allaah be upon him), rather a person may do it on the basis
that it is customary and not the Sunnah of the Prophet (peace and
blessings of Allaah be upon him).
And Allaah knows best.