Investigation in forming Friendships

Kural - 791
To make an untried man your friend is ruin sure;
For friendship formed unbroken must endure.
Meaning : As those who are of a friendly nature will not forsake (a friend) after once loving (him), there is no evil so great as contracting a friendship without due inquiry.
Kural - 792
Alliance with the man you have not proved and proved again,
In length of days will give you mortal pain.
Meaning : The friendship contracted by him who has not made repeated inquiry will in the end grieve (him) to death.
Kural - 793
Temper, descent, defects, associations free
From blame: know these, then let the man be friend to thee.
Meaning : Make friendship (with one) after ascertaining (his) character, birth, defects and the whole of one's relations.
Kural - 794
Who, born of noble race, from guilt would shrink with shame,
Pay any price so you as friend that man may claim.
Meaning : The friendship of one who belongs to a (good) family and is afraid of (being charged with) guilt, is worth even purchasing.
Kural - 795
Make them your chosen friend whose words repentance move,
With power prescription's path to show, while evil they reprove.
Meaning : You should examine and secure the friendship of those who can speak so as to make you weep over a crime (before its commission) or rebuke you severely (after you have done it) and are able to teach you (the ways of) the world.
Kural - 796
Ruin itself one blessing lends:
'Tis staff that measures out one's friends.
Meaning : Even in ruin there is some good; (for) it is a rod by which one may measure fully (the affection of one's) relations.
Kural - 797
'Tis gain to any man, the sages say,
Friendship of fools to put away.
Meaning : It is indead a gain for one to renounce the friendship of fools.
Kural - 798
Think not the thoughts that dwarf the soul; nor take
For friends the men who friends in time of grief forsake.
Meaning : Do not think of things that discourage your mind, nor contract friendship with those who would forsake you in adversity.
Kural - 799
Of friends deserting us on ruin's brink,
'Tis torture e'en in life's last hour to think.
Meaning : The very thought of the friendship of those who have deserted one at the approach of adversity will burn one's mind at the time of death.
Kural - 800
Cling to the friendship of the spotless one's; whate'er you pay.
Renounce alliance with the men of evil way.
Meaning : Continue to enjoy the friendship of the pure; (but) renounce even with a gift, the friendship of those who do not agree (with the world).