8 “God has spoken in His Holy One”....In what Holy One of His? “God was in Christ reconciling the world to Himself.” In that Holy One, of whom elsewhere you have heard, “O God, in the Holy One is Your way.” “I will rejoice and will divide Sichima....and the valley of tabernacles I will measure out.” Sichima is interpreted shoulders. But according to history, Jacob returning from Laban his father-in-law with all his kindred, hid the idols in Sichima which he had from Syria, where for a long time he had dwelled, and at length was coming from thence.
But tabernacles he made there because of his sheep and herds, and called the place Tabernacles. And these I will divide, says the Church. What is this, “I will divide Sichima”? If to the story where the idols were hidden is the reference, the Gentiles it signifies; I divide the Gentiles. I divide, is what? “For not in all men is there faith.” I divide, is what? Some will believe, others will not believe....The shoulders are divided, in order that their sins may burden some men, while others may take up the burden of Christ.
For godly shoulders He was requiring when He said, “For My yoke is gentle, and My burden is light.” Another burden oppresses and loads you, but Christ's burden relieves you: another burden has weight, Christ's burden has wings. For even if you pull off the wings from a bird, you remove a kind of weight; and the more weight you have taken away, the more on earth it will abide. She that you have chosen to disburden lies there: she flies not, because you have taken off a weight: let there be given back the weight, and she flies.
Such is Christ's burden; let men carry it, and not be idle: let them not be heeded that will not bear it; let them bear it that will, and they shall find how light it is, how sweet, how pleasant, how ravishing unto Heaven, and from earth how transporting....Perchance because of the sheep of Jacob, “the valley of Tabernacles” is to be understood of the nation of the Jews, and the same is divided: for they have passed from thence that have believed, the rest have remained without.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)