Then while interviewing for my current doctoral program I discovered a plaque on my supervisor's wall, a quote from Bengel: "Apply yourself wholly to the text; apply the text wholly to yourself."
So I thought I'd try to figure out who this guy was. Evidently Bengel (1687-1752) was a pietistic Lutheran pastor and then scholar in Germany in the 1700s. The way I read his lifespan is by comparing him to my two main historical heroes: he was a contemporary of Jonathan Edwards (1703-58), and he died 100 yrs before Schlatter was born. Six of his 12 children died young. Bengel is known largely for an edition of the Greek NT he compiled.
Anyhow, there is a very old (1837) biography of Bengel, written by John C. F. Burk, and translated from German into English by Robert F. Walker. To indicate the roots of the appreciation of these two men for Bengel: they were both pastors, Burk in Wuertemberg, Germany, Walker in Oxford, England.
Included in this biography are a few letters. Here's an excerpt from a letter written to his mother as he was traveling through Germany that gives a flavor of Bengel and the passions that drove him.
My most dearly beloved and honoured mother,
. . . . I enjoy the consoling assurance, that our faithful God and Father in heaven continues to keep up in you that desire after himself and his everlasting mercy, which has long found its place in your heart; and that he will make it still stronger and more ardent than ever. O yes, this one thing is that which 'our soul longeth after' in the present transitory state. The few days that may yet remain to us in this life, cannot be more happily spent that in seeking, with constant care and diligence, to become partakers of the heavenly inheritance. Great as this inheritance is, its attainment is secured, if we only heartily desire, accept, and lay hold of it. In ourselves we have neither strength nor worthiness for that purpose; nor can any prosper spiritually who have not known and felt the reality of their own wretchedness, misery, poverty, blindness, and unfitness for all good. But in Christ Jesus are freely bestowed for our everlasting possession, the forgiveness of sins, the gift of righteousness, the peace of God, spiritual rest, consolation, joy, strength, life, fullness of content and satisfaction; and we have only to prostrate ourselves before the throne. . . .
And now I commit all this to that sure and certain blessing, the gracious favour of my faithful God and yours. On him let us venture all; to him let us commit every thing. . . .
--John C. F. Burk, A Memoir of the Life and Writings of John Albert Bengel (London: William Ball, 1837), pp. 30-32; italics original