Ambrose of Milan

Sitting we speak against others, but standing up we praise the Lord, as it is said; "Behold now, praise the Lord, all ye servants of the Lord; ye that stand in the house of the Lord." He who sits, to speak of the habit of the body, is, as it were, dissolved by ease, and relaxes the energy of his mind. But the careful watchman, the unwearied scout, the wakeful sentinel who keeps the outposts of the camp, these stand. The brave warrior also, who would prevent the designs of his enemy, stands ready in his rank ere he is looked for.

Letter 63: To the church of Vercellae ↗

Jerome

Behold now, bless the Lord, all you servants of the Lord. This is the last psalm of the Song of Ascents. The first of the gradual psalms had been: 'To the Lord, when I was in tribulation, I cried, and he heard me.' In the second he had climbed higher: 'I lifted up my eyes to the mountains.' In the third: 'I rejoiced in the things that were said to me.' In the fourth: 'To you I have lifted up my eyes, you who dwell in heaven.' See how little by little he ascends through the steps, and arrives at loftier things. …

Homily 46, on Psalm 133 ↗