This past weekend, an extract from a long psalm served as the entrance antiphon. The 106th is an interesting choice (as the conclusion of a community lament) to yoke to the 122nd, a psalm for the pilgrimage to Jerusalem.
Entrance Antiphon Ps 105: 47
Save us, O Lord our God!
And gather us from the nations,
to give thanks to your holy name,
and make it our glory to praise you.
(Psalm 121: GS, p. 242)
Another lament is given as the first choice for Communion (Psalm 31 appears after the first reading on Good Friday):
Communion Antiphon Cf. Ps 30: 17-18
Let your face shine on your servant.
Save me in your merciful love.
O Lord, let me never be put to shame, for I call on you.
(Psalm 30: 2-6, 8ab, 15-16a: GR, p. 271)
Alternatively, one can choose a refrain from the Beatitudes and use it with the standby, Psalm 34, or perhaps a better link, the 37th Psalm which responds to the seeker who asks about the prosperous wicked, and in turn is told: just wait; God will turn things on their head.
Or: Mt 5: 3-4
Blessed are the poor in spirit,
for theirs is the Kingdom of Heaven.
Blessed are the meek, for they shall possess the land.
(Psalm 33 or Psalm 36: 1, 3, 16, 18, 23, 27: cf. GR, p. 514)
These passages all work pretty well for a cycle A Sunday in which the Beatitudes are proclaimed. But in cycle B, we read of Moses’s warning about false prophets and Jesus’s first cure of a possessed person early in his public ministry.
As a generic prayer for gathering, I suppose the 122nd Psalm is suitable enough for entrance. But for Communion, If I were going outside the Psalter, I might suggest an extended passage from Baruch. A shorter version of this is read at the Easter Vigil (if you are doing more than the minimum four to five readings).
How vast is the house of God,
how broad the scope of divine dominion:
vast and endless, high and immeasurable.
Or if I were considering the New Testament, a call to be built into a spiritual house. Which complements Psalm 122 somewhat:
(Psalm 118:22/1 Pet 2:7b)
The stone which the builders rejected
has become the cornerstone.
(1 Peter 2:1-10)