Walk in place during lines 1, 2, and 4 (or walk in a circle if your Primary is small).
Stop and do actions for line 3:
They washed at streams (rub your hands together as if you're washing them)
and worked (hammer one fist on top of the other)
and played (pretend to throw a ball)
Sundays they camped (hands make a tent roof)
and read (hands make a book)
and prayed (fold arms)
[Explain that "camped" means stayed put instead of walking. Discuss keeping the Sabbath day holy. Notice this is the only time during the song you are not walking.]
Every time you sing the word "walked" scoot over one chair.
Use the same actions as Jr. for the third line, including the Sabbath Day discussion.