Note: This suggestion is similar to that of Murai. A and A’ refer to the wicked and make anatomical references. B and B’ refer to the mercy and righteousness of the LORD. Verses 5 and 6 may be referring to the water cycle which is paralleled in 8-10. Verse 7 I suggest is the centre which is the middle reference to the chesed mercy of God.
A. 1 The transgression of the wicked saith within my heart,
that there is no fear of God before his eyes.
2 For he flattereth himself in his own eyes,
until his iniquity be found to be hateful.
3 The words of his mouth are iniquity and deceit:
he hath left off to be wise, and to do good.
4 He deviseth mischief upon his bed;
he setteth himself in a way that is not good;
he abhorreth not evil.
B. 5 Thy mercy (chesed), O LORD, is in the heavens;
and thy faithfulness reacheth unto the clouds.
6 Thy righteousness is like the great mountains;
thy judgments are a great deep:
O LORD, thou preservest man and beast.
C. 7 How excellent is thy lovingkindness, O God!
therefore the children of men put their trust under the shadow of thy wings.
B’. 8 They shall be abundantly satisfied with the fatness of thy house;
and thou shalt make them drink of the river of thy pleasures.
9 For with thee is the fountain of life:
in thy light shall we see light.
10 O continue thy lovingkindness (chesed) unto them that know thee;
and thy righteousness to the upright in heart.
A’. 11 Let not the foot of pride come against me,
and let not the hand of the wicked remove me.
12 There are the workers of iniquity fallen:
they are cast down, and shall not be able to rise.