Another interpretation: "And one rises up at the voice of the bird" (Ecclesiastes 4). Just as the young of the bird lean toward their father, that he may come and put <food> into their mouths, so does he (the aged one) wait for someone to come and put <food> into his mouth. "And all the daughters of song are brought low" (Ecclesiastes 4) — these are the lips, for all the days that one is young his voice goes forth, but once he grows old they (the lips) become flabby, and his voice does not travel.
When the Aged Wait at the Voice of the Bird in Chayei Sara
Midrash Tanchuma Buber, Chayei Sara 7:10
ד"א ויקום לקול הצפור. כשם שבני הצפור מטין לאביהן שיבא ויתן לתוך פיהם, כך הוא מקוה למי שיבא ויתן לתוך פיו. וישחו כל בנות השיר (קהלת ד), אלו השפתים, שכל ימיו שהוא בחור קולו יצא, וכיון שמזקין הן מתרפות ואין קולו הולך.