Seek his soul - i. e., "Care for, watch over, his life" (compare Psalm 142:4).

The bloodthirsty hate the upright,.... Cain did Abel; and as the wicked world hate all good men, and persecute them, even unto death;
but the just must seek his soul; either the soul of the bloodthirsty, and that either the good of their souls; seek their spiritual welfare, and pray for it, even though they are so cruel and inhuman: or just magistrates will seek after such persons, to punish them for shedding the blood of the upright. Or else the meaning is, that just persons seek the soul of the upright, and make inquisition for the blood of such, to punish for it; which comes to the same sense, as Aben Ezra observes: or rather, such seek to defend and preserve the soul or life of upright men from those that hate and persecute them. Jarchi illustrates it by 1-Samuel 22:23; the Targum is,
"men that shed blood hate integrity; but the upright seek it.''

Christ told his disciples that they should be hated of all men. The just, whom the blood-thirsty hate, gladly do any thing for their salvation.

bloodthirsty--(Compare Margin), murderers (Psalm 5:6; Psalm 26:9).
hate, &c.-- (Proverbs 1:11; Genesis 3:4).
seek . . . soul--that is, to preserve it.

We now group together Proverbs 29:10-14. Of these, Proverbs 29:10 and Proverbs 29:11 are alike in respect of the tense used; Proverbs 29:12-14 have in common the pronoun pointing back to the first member.
10 Men of blood hate the guiltless
And the upright; they attempt the life of such
The nearest lying translation of the second line would certainly be: the upright seek his soul (that of the guiltless). In accordance with the contrasted ישׂנאו, the Aram. understand the seeking of earnest benevolent seeking, but disregarding the נפשׁ in לנפשׁו;
(Note: The Targum translates תם, guiltlessness, and the Venet. (μισοῦσι) γνῶσιν, turning to Proverbs 1:22.)
Symmachus (ἐπιζητήσουσι), Jerome (quaerunt), and Luther thus also understand the sentence; and Rashi remarks that the phrase is here לשׁון חבּה, for he rests; but mistrusting himself, refers to 1-Samuel 21:1-15 :23. Ahron b. Josef glosses: to enter into friendship with him. Thus, on account of the contrast, most moderns, interpreting the phrase sensu bono, also Fleischer: probi autem vitam ejus conservare student. The thought is, as Proverbs 12:6 shows, correct; but the usus loq. protests against this rendering, which can rest only on Psalm 142:5, where, however, the poet does not say אין דּורשׁ נפשׁי, but, as here also the usus loq. requires, לנפשׁי. There are only three possible explanations which Aben Ezra enumerates: (1) they seek his, the bloody man's, soul, i.e., they attempt his life, to take vengeance against him, according to the meaning of the expressions as generally elsewhere, used, e.g., at Psalm 63:10; (2) they revenge his, the guiltless man's, life (lxx ἐκζητήσουσιν), which has fallen a victim, after the meaning in which elsewhere only בּקּשׁ דּם and דּרשׁ נפשׁ, Genesis 9:5, occur. This second meaning also is thus not in accordance with the usage of the words, and against both meanings it is to be said that it is not in the spirit of the Book of Proverbs to think of the ישׁרים [the upright, righteous] as executors of the sentences of the penal judicature. There thus remains
(Note: For εὐθεῖς δὲ συνάξουσιν (will bring away?) τὴν ψυχὴν αὐτῶν, understood after Jeremiah 45:5, lies linguistically yet further off.)
the interpretation (3): the upright - they (the bloody men) seek the soul of such an one. The transition from the plur. to the sing. is individualizing, and thus the arrangement of the words is like Genesis 47:21 : "And the people (as regards them), he removed them to the cities," Gesen. 145. 2. This last explanation recommends itself by the consideration that תם and ישׁרים are cognate as to the ideas they represents-let one call to mind the common expression תּם וישׁר [perfect and upright, e.g., Job 1:1; Job 2:3], - that the same persons are meant thereby, and it is rendered necessary by this, that the thought, "bloody men hate the guiltless," is incomplete; for the same thing may also be said of the godless in general. One expects to hear that just against the guiltless, i.e., men walking in their innocence, the bloody-mindedness of such men is specially directed, and 10b says the same thing; this second clause first brings the contrast to the point aimed at. Lutz is right in seeking to confute Hitzig, but he does so on striking grounds.

Seek - To preserve it.