Praise be to Allah.
In the answer to question no. 131579, we mentioned the difference of opinion among the scholars concerning how the right hand should be between the two prostrations: should the fingers be outspread on the thigh, or should one point with the forefinger as is done during the tashahhud?
When the worshipper sits between the two prostrations or during the tashahhud, he should look at his forefinger; some scholars say that he should look at his lap.
An-Nasaa’i (1160) narrated from ‘Abdullah ibn ‘Umar (may Allah be pleased with him) that he described the way the Prophet (blessings and peace of Allah be upon him) sat in the prayer. He said: He placed his right hand on his right thigh, and pointed with his finger that is next to the thumb towards the qiblah, and he focused his gaze on it or thereabouts. Classed as saheeh by al-Albaani in Saheeh an-Nasaa’i.
Shaykh Ibn Baaz (may Allah have mercy on him) was asked: Where should the worshipper look when he is praying?
He replied: The Sunnah is for him to look at the place of his prostration whilst he is standing and also when bowing. But when he is sitting, he should look at his pointing finger when he sits for the tashahhud or between the two prostrations; he should look at his pointing finger, as is mentioned in the Sunnah from the Prophet (blessings and peace of Allah be upon him). End quote.
Majmoo‘ Fataawa Ibn Baaz (29/241)
Shaykh Ibn Jibreen (may Allah have mercy on him) was asked: When reciting the tashahhud, should the worshipper look at the place of prostration or should he look at his forefinger when raising it to express the oneness of Allah (Tawheed)?
When he is sitting between the two prostrations or for the tashahhud, he should look at his forefinger or at his hands. But when he is standing, he should look at the place of his prostration. All of that is so that his thoughts will not wander, lest distracting ideas and waswaas (whispers from the Shaytaan) come to him whilst he is praying. End quote
Sharh ‘Umdat al-Ahkaam (21/14)
An-Nawawi (may Allah have mercy on him) narrated in al-Majmoo‘ from some of the Shaafa‘is that when sitting, the worshipper should look at his lap. This was also narrated by as-Sarkhasi in al-Mabsoot from at-Tahhaawi (may Allah have mercy on them all).
And Allah knows best.
Source: Islam Q&A