It was a 3rd and 5 from the 35. This was the drive sequence (attached below). They went for it on 4th down and threw an incompletion on a deep pass to Gronk (a stereotypical throw long on short distance Rodgers/MM move). The Eagles were up 9-3 at that point and if Brady catches that pass it's at least 9-6. If they run up the middle and gain 2-3 yards instead of the trick play, they may even try the FG at that point.
Instead, they don't convert on 4th down, then the Eagles drive to go up 15-3. It was a huge turning point in the game as it set up the Patriots to have to battle back from a deep hole the rest of the game. The two trick plays to the QBs were the difference in the game. The Eagles gained 4 points on the Foles catch (as compared to a chip shot FG) and the Patriots lost at least 3 and more likely 7 points on Brady not being able to make the play.
1st and 10 at NE 37
(13:11 - 2nd) T.Brady pass deep left to B.Cooks to PHI 40 for 23 yards (M.Jenkins) [N.Bradham]. NE-B.Cooks was injured during the play. He is Out.
1st and 10 at PHI 40
(12:49 - 2nd) (Shotgun) T.Brady pass incomplete short left to J.White (M.Jenkins) [T.Jernigan].
2nd and 10 at PHI 40
(12:45 - 2nd) D.Lewis up the middle to PHI 35 for 5 yards (N.Bradham; C.Graham).
3rd and 5 at PHI 35
(12:04 - 2nd) (Shotgun) D.Amendola pass incomplete short right to T.Brady.
4th and 5 at PHI 35
(11:58 - 2nd) (Shotgun) T.Brady pass incomplete deep right to R.Gronkowski (J.Mills) [B.Graham].