What are the connotations of "Shalosh Regalim"?
Rashi, Targum Onkelos and Targum Yonasan: It means three times a year. 1
Chagigah, 4a: It means three foot-festivals, on which one is obligated to go up to the Beis-ha'Mikdash on foot. Consequently, someone who has a wooden leg, 2 who is lame (even in one leg - Chagigah, 3a) sick, blind, old or who is unable to walk (or a Katan who is unable to hold his father's hand and ascend Har ha'Bayis together with him 3 - Chagigah, 2a) is exempt from Aliyas ha'Regel on Yom-Tov ah - Chagigah, 2a).
As in Balak Bamidbar, 22:28 (Rashi).
See Torah Temimah, note 94. The Gemara there also learns it from the words "Shalosh Pe'amim" in Pasuk 16, which it equates with "Shalosh Regalim".
See Torah Temimah, note 92.
Why does the Torah insert the Shalosh Regalim in the Parshah of Sh'mitah?
What are the connotations of the words "Tachog Li"?
Seforno: It means 'Celebrate (rejoice) with Me (Hashem). 1
Targum Onkelos and Targum Yonasan: It means 'Celebrate before Me (Hashem)'.
As the Pasuk writes in Tehilim, 149:2, "Yismach Yisrael be'Osav" - as opposed to the Pasuk in Sh'mos 32:19 "Vayar es ha'Eigel u'Mecholos" (Seforno).