Reference for Yevamot 227:11
אבא שאול אומר נוהגין היינו שיונקים מבהמה טהורה ביום טוב: היכי דמי אי דאיכא סכנה אפילו בשבת נמי ואי דליכא סכנה אפילו ביום טוב אסור לא צריכא דאיכא צערא
— [Permissibility for] an adult is dependent on medical opinion.<span class="x" onmousemove="('comment',' Lit., 'requires an estimate'. Before he is allowed to eat of the forbidden food it is necessary to obtain medical opinion that delay until the conclusion of the Sabbath, for instance, would involve him in danger. ');"><sup>46</sup></span> [Permissibility for] a child also should be made dependent on medical opinion!<span class="x" onmousemove="('comment',' Cf. supra n. 11. ');"><sup>47</sup></span> — R. Huna son of R. Joshua replied: The ordinary child is in danger when deprived of his<span class="x" onmousemove="('comment',' Lit., 'at'. ');"><sup>48</sup></span> milk. 'Abba Saul stated: It was our practice to suck from a clean beast on a festival'. How is one to understand this?<span class="x" onmousemove="('comment',' The circumstances in which Abba Saul and his friends were permitted to commit an apparently forbidden act. ');"><sup>49</sup></span>