Hâgâh (הָגָה, Strong's #1897), “to meditate, moan, growl, utter, speak.” This word is common to both ancient and modern Hebrew. Found only 25 times in the Hebrew Old Testament, it seems to be an onomatopoetic term, reflecting the sighing and low sounds one may make while musing, at least as the ancients practiced it. This meaning is seen in its first occurrence in the text: “This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night …” (Josh. 1:8). Perhaps the most famous reference “to meditating” on the law day and night is Ps. 1:2.
Hâgâh also expresses the “growl” of lions (Isa. 31:4) and the “mourning” of doves (Isa. 38:14). When the word is used in the sense of “to mourn,” it apparently emphasizes the sorrowful sounds of mourning, as seen in this parallelism: “Therefore will I howl for Moab, and I will cry out for all Moab; mine heart shall mourn for the men of Kir-heres” (Jer. 48:31). The idea that mental exercise, planning, often is accompanied by low talking seems to be reflected by Prov. 24:1-2: “Be not thou envious against evil men, … for their heart studieth destruction, and their lips talk of mischief.”