This is one of the shortest psalm in Psalms. This psalms talks about peace and how good it will be when brothers are in united spirit and worship the Lord. Jews sing this psalm during their Sabbath gathering, especially during the time they are ready to go home after worship... Hodu L'adonai Ki Tov, Kille Olam Khasdo.... This nice cultural song, create the ambience of peace...

Psalms Chapter 133
א שִׁיר הַמַּעֲלוֹת, לְדָוִד:הִנֵּה מַה-טּוֹב, וּמַה-נָּעִים-- שֶׁבֶת אַחִים גַּם-יָחַד.

1 A Song of Ascents; of David. {N}Behold, how good and how pleasant it is for brethren to dwell together in unity!

ב כַּשֶּׁמֶן הַטּוֹב, עַל-הָרֹאשׁ--יֹרֵד, עַל-הַזָּקָן זְקַן-אַהֲרֹן:שֶׁיֹּרֵד, עַל-פִּי מִדּוֹתָיו

2 It is like the precious oil upon the head, {N}coming down upon the beard; even Aaron's beard, {N}that cometh down upon the collar of his garments;

ג כְּטַל-חֶרְמוֹן-- שֶׁיֹּרֵד, עַל-הַרְרֵי צִיּוֹן:כִּי שָׁם צִוָּה יְהוָה, אֶת-הַבְּרָכָה--חַיִּים, עַד-הָעוֹלָם.

3 Like the dew of Hermon, that cometh down upon the mountains of Zion; {N}for there the LORD commanded the blessing, {N}even life for ever. {P}