The instructor ordered the recruits to stand at ease.
Tips
usage
The shào reading appears in essentially one word: 稍息 — the military command 'stand at ease!', the counterpart to 立正 'attention!' Outside this drill-ground use, 稍 is read shāo.
memory
Mnemonic: a barked command needs a falling fourth tone — 稍息! Picture a row of recruits snapping to rest; the sharp shào matches the bark of the order.
Grain radical — same glyph as the shāo reading. The shào pronunciation is a borrowed military reading filed on the same character; the grain-tip etymology belongs to the shāo sense.
Right phonetic 肖 — supplies the sound. Under the shào reading the tone shifts to fourth, marking this as a specialized command-register use rather than a separate etymology.