guidelines for will making

O you who believe! When death approaches any of you, and you make a bequest, (then take) the testimony of two just men of your own folk or two others from outside, While you are travelling through the land and death befalls you. Detain them both after As-Salât (the prayer), (then) if you are in doubt (about their truthfulness), let them both swear by Allâh (saying): "We wish not for any worldly gain in this, even though he (the beneficiary) be our near relative. We shall not hide Testimony of Allâh, for then indeed we should be of the sinful."

If then it gets known that these two had been guilty of sin, let two others stand forth in their places, nearest in kin from among those who claim a lawful right. Let them swear by Allâh (saying): "We affirm that our testimony is truer than that of both of them, and that we have not trespassed (the truth), for then indeed we should be of the wrong¬doers."

That should make it closer (to the fact) that their testimony would be in its true shape (and thus accepted), or else they would fear that (other) oaths would be admitted after their oaths. And fear Allâh and listen ( with obedience to Him). And Allâh guides not the people who are Al-Fâsiqûn (the rebellious and disobedient).

Al maeda 106-108