Tafsiran Rut 2:17: Ibn Ezra

And it was about an ephah of barley. Once a man asked me, what is the significance of 'an ephah of barley'. I told him there is no point to the question because the text simply reports what happened. I appeared foolish in his eyes, and he told me there was indeed a meaning, but I remained silent and did not ask him. Then, one day he came and told me that there are many reasons.

One reason is that Ruth saw prophetically that one of her descendants would establish a pillar in the name of her husband, and the term 'ephah' - alludes to the 166 pomegranates that were on the pillar, which in gematria (numerical value) equals 'ephah', and 'barley' as in 'measures' like 'measure of his life'. Another reason, 'and it was' - these two words, one in Aramaic and one in Hebrew. It signifies when she saw that Absalom, one of her descendants, would be hanged, and the letters 'kaf' and 'aleph' hint at the years of Absalom's life until his death. And then 'an ephah of barley' - in plural form, because it was a heavy burden for him. Another reason is that the initial letters of 'ephah' and 'barley' together make 'Jesse' in gematria, who was a complete righteous man. Then he rejoiced and his heart settled within him.