Musar zu Tehillim 32:11

I hold that this quality is to be found in the souls of those, above all, who are free from defilement, the righteous, the pious, the pure, destined for the Heavenly Kingdom, rising to spirituality, i.e., the souls of the upright, for they are in perfect enjoyment of their condition of service and greatly rejoiced because of their worship, as it is written (Ps. xxxii. 11), "Be glad in the Lord and rejoice, ye righteous; and shout for joy, all ye that are upright in heart." The well-bred man ought not to indulge in laughter when seated in an assembly, for it was said that for him who laughs much, but little respect is felt. Facetiousness takes away the veil of dignity. Even as anxiety (apprehensiveness) when it is aroused gives rise to weeping, so gladness, when it is stirred, incites to laughter.